The aim of the Department of Social Protection in means testing for job seeker's allowance individuals who are seeking employment is not the same as the Revenue Commissioners in administering tax credits which are available for offset against liability to income tax on earnings. The basis for the current tax treatment of married couples derives from the Supreme Court decision in Murphy vs. the Attorney General (1980), which held that it was contrary to the Constitution for a married couple, both of whom are working, to pay more tax than two single people living together and having the same income.
The Taxes Consolidation Act 1997 provides for the granting of tax credits based on the civil status of the claimant. A person who is single is entitled to a basic personal credit of €1,650 and this is doubled to €3,300 for a married couple or civil partners who are jointly assessed. Should the couple choose separate treatment or single assessment, each individual is entitled to a personal credit of €1,650. Married couples or civil partners can transfer tax credits and tax bands between the individuals, and this is of benefit where one of the individuals earns less that the 20% tax threshold of €32,800 or where one of the individuals has no income.
A cohabiting couple where both partners are working also get, in total, the same tax credits as a married couple or couple in a civil partnership (i.e. €3,300). However, they are treated as separate and unconnected individuals for the purpose of income tax and, accordingly, credits, tax bands and reliefs cannot be transferred from one partner to the other. The treatment of cohabiting couples for the purposes of social welfare is primarily a matter for the Minister for Social Protection. However, it is also based on the principle that married couples should not be treated less favourably than cohabiting couples. This was given a constitutional underpinning following the Supreme Court decision in Hyland v Minister for Social Welfare (1989) which ruled that it was unconstitutional for the total income a married couple received in social welfare benefits to be less than the couple would have received if they were unmarried and cohabiting.